20x102 all plastic and with plastic drive-band projectiles


#1

Hello,
I’ve got some questions about these 3 experimental 20x102 projectiles i recently aquired.

First one is supposed to be an experimental plastic driveband ‘short type sleeve’ with white plastic

Second one is supposed to be an experimental plastic driveband ‘long type sleeve’ with semi-transparent plastic

And the third one was described to me as an experimental ‘all plastic’ incendiary projectile

Now, is there someone who can confirm these are correctly identified ?
And if anyone has some information on either of the projectiles, it sure is welcome (i have nothing about them for now…)

Thanks,
Geert.


AC 130 gunship in action
#2

Geert,

Something you may want to look at is DTIC report ADBOO0170: dtic.mil/dtic/tr/fulltext/u2/b000170.pdf DEVELOPMENT OF A PLASTIC ROTATING BAND FOR HIGH PERFORMANCE PROJECTILES

Brian


#3

Hi Brian,

I did read the ADBOO0170, and i sure agree that the 2 first rounds could be part ot that test, but all the ‘examples’ quoted in the text have special adapted anchorage points for the driveband (serations, grooves,…), and just one of those had a “Projectile With Over-The-End Rotating Band”

my 2 projectiles seem to have a regular driveband underneath the plastic/teflon.
The projectile has no crimp groove visible underneath the transparant plastic, so i guess it’s not an altered ordinary TP…


#4

Geert,

Experimental plastic bodied (injection molded) 20mm projectiles are covered/pictured on pages 164 - 167 of Historical Development of Automatic Cannon Ammunition: 20 mm to 30 mm; Davis, D.M., 1984. The last projectile you show is listed and pictured as a “structural and incendiary damage projectile”. Development dates from the late 1960’s to early 1970’s, work done at AAI Corp. It contains a “mischmetal” core for incendiary effect on impact and the nose is Teflon.

Brian


#5

Thanks Brian !


#6

Brian, thanks for the doc - as usual.

So if I got you right the core is pyrophoric? And as it says “Mischmetall” (metal mix) do you happen to know the composition?


#7

Alex,

Davis does not list the constituent materials in the mischmetal core; quote from his discussion:

“…we were investigating the incendiary effects of mischmetal and had also observed that many plastics, being chlorinated or fluorinated hydrocarbons, tended to be good oxidizers, apparently releasing fluorine or chorine when subjected to explosive or high impact loads.” “…an enhancement of incendiary effect was obtained by substituting a Teflon nose plug.”

He provides a picture of the core, but the pictures are all black and white.

He latter mentions that, at the time, these plastic bodied projectiles, when fired in a hot gun resulted in bad things happening in the barrel, ending up with wide dispersion or projectile break-up.

Brian


#8

Too bad there is no info on the composition. I would have guessed on things like Magnesium, Titanium and others.

Plastic and hot barrels are always a sensitive issue I guess. Though we see today quite some plastic driving bands.


#9

This appears to be a patent relating to the plastic incendiary projectile in question:

http://www.google.com/patents/US4096804

From the above page, "Mischmetal is a commercially available mixture of about 50% cerium, 25% lanthanum and a mixture of other rare earths. A preferred alloy of mischmetal/aluminum is made up of 87% mischmetal and 13% aluminum. "


#10

Plastic bodied projectiles (20mm), page 165 from Historical Development of Automatic Cannon Ammunition: 20 mm to 30 mm.

The projectile Geert shows above appears to be the same as projectile “G” in the picture, item “D” is the mischmetal core used in projectile “G”.

.


#11

Brian, Chip,

Thanks for the additional picture (way better than the one i have in my copy of the AD-A140367) and the patent.
Now the third projectile is 100% identified

l sure hope someone has similar valueable info to identify the first 2 projectiles.

Thanks,
Geert.


#12

From DTIC, a bit more info. Unfortunately this report is not available as a PDF.

Accession Number : AD0919852

Title : 20MM Plastic/Misch Metal Incendiary Projectile.

Descriptive Note : Final rept. May-Dec 73,

Corporate Author : ORLANDO TECHNOLOGY INC FL

Personal Author(s) : Fuehrer, Hans R. ; Kitchin, Thurman D. ; Keeser, John W.

Report Date : FEB 1974

Abstract : This report summarizes an eight-month program to develop a less complex and expensive 20mm incendiary projectile which is equal to or greater than the M56 A3/A4 HEI in incendiary effects against aircraft fuel cells. The approach consists of: EMPLOYING THE PYROPHORIC PROPERTIES OF MISCH METAL ALLOYS FOR INCENDIARY CAPABILITY; USING A PLASTIC JACKET FOR LOW COST AND LOW BARREL WEAR, AND ENVIRONMENTALLY SOUND ENCAPSULATION OF THE MISCH METAL CORE; OPTIMIZING MISCH METAL CORE MATERIAL AND CONFIGURATION WITH REGARD TO INCENDIARY EFFECTS AND BALLISTIC STABILITY; AND FABRICATING 1500 PROJECTILES OF THE FINAL DESIGN FOR FURTHER TEST AND EVALUATION (Author, modified-PL)